Milling cutter



1936' F. KINZBACH MILLING CUTTER Filed Oct. 31, 1933 Patented May 5, 1936 l UNITED STATES PATENT OFFICE 2,039,427 MILLING CUTTER Frank Kinzbach, Houston, Tex.

Application October 31, 1933, Serial No. 696,013

3 Claims. (Cl. 29-105) This invention relates to a milling cutter. meral I designates the cutter head. This head One object of the invention is to provide a is substantially cylindrical but its free, or nose, cutter of the character described specially deend is beveled or tapered, all the way around, as signed for the purpose of perforating the side of a shown at 2. The cylindrical portion of the head casing in a well bore when it becomes necessary has the spiralled cutting blades 3 set in grooves 5 to side track the bore in drilling a well. in the head with their nose ends 4 slightly bev- In drilling a well circumstances often arise eled off to conform to the pitch of the beveled making it impossible, or undesirable to continue portion 2. In staggered relation with the blades 3 the original bore and it then becomes necessary are the lower end blades 5, 5', which are set in to perforate the casing in the bore and form a grooves in the beveled end 2 of the head. These 1 new bore beneath the perforation. In doing this blades 5, 5' are preferably straight, that is each side tracking, a whip stock, of conventional conblade lies in a plane passing through the axis of struction, is secured in the casing at or near the head. The adjacent ends of the blades 3 and where the casing is to be perforated, said whip- 5, 5' ov rlap but ar pac d apart th pr v i stock having an upwardly sloping face and the ample cutting edges at the point where the most 15 milling tool is attached to a stem and let down Work is required, and the other ends of the blades into the casing, and rotated between said sloping 5' ext nd radia ly across the tapered end of face and the side of the casing until a perfora- Said head.

tion is cut through said casing. The milling tool One end of the head has a taper t a ly herein described is specially designed for said t aded bOX 6 to receive the adjace t nal y 20 w rk, threaded portion 1 of a drill stem 8. The head A th bj t of th i ti i t provide also has a central water course 9 therethrough a milling cutter of the character described havso that flush wat m y b supp i d to the ihg spiralled i cutting bl d d having work and the lower ends of the blades 5 extend tapered r beveled nose provided with end cuijacross the lower end of the head to the water 25 ting biades which are staggered t respect t course 9 and the lower ends of the blades 5' exth d l d d are disposed i common ten-d across the lower end of the head and into planes th th axis of t t of th tt r said water course. If the water course were enhead, the adjacent ends of the side cutters and tirely Open the milling tool, as t al y cuts nose cutters overlapping so as to provide ample through the p p might m a r r proi 30 cutting edges at the point of greatest work of tion, in S0 perforating the g, Which du th 1, operations in withdrawing and re-inserting the A further feature of the invention resides in i ling tool, might become distorted or bent inthe provision of a, milling tool having a, head and wardly and form an obstruction that would intercutters, as described removably mounted therein, fele With the Work, Which might prevent the and provided with a central water course theremilling 13001 from aking a compl perforation. through with the inner ends of some of th d such as would permit side tracking therethrough. biades projecting t t water course for th The fact that the blades 5' project into the water purpose described w t t above and other course 9 will permit the transverse lower ends of 40 objects in view, this invention has particular relat e blades 5, 5 to remove the whole of the area 40 tion to certain novel features of construction, ardefined by the lower Of the Glitter and Drerangements of parts and an example of vent the formation of this core or projection in which is given in this specification and illustratmaking the initial p o tion.

ed in accompanying drawing, whereinz- The blades 3, 5 and 5' are removable so that Figure 1 shows a side elevation of the device when they become broken or worn they can be 45 in operation in a pipe to be perforated. removed for the insertion of the new ones, and Figure 2 shows avertical sectional view thereof the cutting edges of the blades 3 are slightly taken on the line 22 of Figure 3, curved outwardly as shown so that said edges will Figure 3 shows an end view thereof. assume an angular relation with the material Figure 4 shows a fragmentary side view, and, being operated on and will more readily shear off 50 Figure 5 shows a fragmentary vertical sectional said material. view. While I have shown what I now consider to be Referring now more particularly to the drawthe preferred form of the invention it is obvious ing, wherein like numerals of reference desigthat mechanical changes may be made therein nate similar parts in each of the figures the nuand equivalents substituted for the parts shown 55 and I reserve the right to make such mechanical changes and substitutions as may be comprehended within the principle of the invention.

What I claim is:

1. A milling tool including a substantially cylindrical head having a water course therethrough, said head having threads at one end for the connection of a driving stem thereto and being tapered at the other end forming an annular beveled face, a series of side cutting blades on the cylindrical portion of the head whose lower ends overlap said face, at its upper margin only, and are beveled to conform to the shape of said beveled face and a series of end cutting blades on said beveled face whose upper ends overlapthe lower end only of said cylindrical portion and are beveled to conform to the beveled lower ends of said side cutting blades, said beveled portions of said blades being staggered with respect to each other, the adjacent beveled ends of the blades of the respective series overlapping, and the other ends of said end blades extending radially across the end of the head to said water course and some of said last mentioned blades projecting into the water course.

2. A milling tool comprising asubstantially cylindrical head and being externally beveled at its upper end, said head having an approximately axial water course therethrough and being threaded at its upper end for the connection of a driving member thereto, the lower end of said head being tapered, forming an annular beveled face, a series of side-cutting blades on the cylindrical portion of the head whose upper ends are beveled and whose lower ends overlap said beveled face, the overlapping portions of said blades being beveled to correspond to the bevel of said face, a series of cutting blades on said beveled face and staggered with respect to the side-cutting blades, the upper ends of said end cutting blades overlapping the lower portion of the cylindrical surface of the head, said overlapping ends of said end blades being beveled, all of said blades having flat outer surfaces which terminate in cutting edges at the forward margins of the blades, the lower portions of the end cutting blades extending approximately radially across the lower end of the head, the inner end of at least one of said end blades projecting into the water course, and the inner ends of the other end blades terminating adjacent the wall of said water course, all of said inner ends lying closely adjacent each other to completely shield the lower end of the head around the water course.

3. A milling tool comprising a substantially cylindrical head and being externally beveled at its upper end, said head having an approximately axial water course therethrough and being threaded at its upper end for the connection of a driving member thereto, the lower end of said head being tapered, forming an annular beveled face, a series of side-cutting blades on the cylindrical portion of the head whose upper ends are beveled and whose lower ends overlap said beveled face, the overlapping portions of said blades being beveled to correspond to the bevel of said face, a series of cutting blades on said beveled face and staggered with respect to the side-cutting blades, the upper ends of said end cutting blades overlapping the lower portion of the cylindrical surface of the head, said overlapping ends of said end blades being beveled, all of said blades having fiat outer surfaces which terminate in cutting edges at the forward margins of the blades, the

lower portions of the end cutting blades extend- 

